The anti-hero

An anti-hero is a hero with unheroic qualities; such as Batman. Batman undoubtedly does good, as he swoops in and "BOW, WHAP, POK!s" his enemies, but he's got a huge dark side. He dresses as a black bat, will resort to violent torture methods, is occasionally obsessed with his alter-ego. He's been on the other side of the law, if only for a little while.

Anti-heroes are very flawed; it's what they are. They have deep doubts, or deep trauma, and it shows. They either persevere through it and come out a better person, or they fall to the dark. Undoubtedly to come back again, but it's still a story arc.

Anti heroes can be written really well, but it takes some skill to get an anti-hero above adequate. You have to make sure the audience cares about him and wants him to get better, but also have the audience revelling in the drama of his ups and downs.

Don't overdo the anti-hero. There have been a lot of anti-heroes in fiction as of late, and the reader will see right through the anti-hero's typical plotline if you don't stray from it.

I'll put a cliche warning here: ever heard of a good guy going evil, and then the rest of them go "Oh god he's evil now! Come back!" and the previously good but now evil guy goes "I can't." but he's obviously thinking about it, and then at the perfect moment he rebels, and the good guys win?

Avoid that. And other anti-hero cliches you see, for that matter.

My verdict: anti-heroes in moderation.